ANN ARBOR, MI – The cross/utility market continues to fragment, with auto makers increasingly chasing after subsets of buyers looking for the perfect combination of comfort, fuel economy and agility.

Mercedes-Benz’s GLK, its smallest CUV, has been a steady seller for the brand, routinely notching monthly deliveries north of 2,000 units, according to WardsAuto data. The M-Class SUV is the breadwinner for Mercedes’ trucks with monthly sales regularly standing above 3,000.

The GLK350 was introduced in 2009 and received a major overhaul in 2012. For 2013, Mercedes introduces the GLK250, which shares the same body but has a diesel engine under the hood.

Mercedes says the current gasoline-powered GLK appeals mainly to wealthy, childless Generation X and Baby-Boomer buyers. As the U.S. ratchets up fuel-economy standards, the luxury marque is looking to get a jump on the trend by adding the diesel version, already available in Europe, while preserving its customer base.

The auto maker says diesels account for 6% of its overall U.S. sales. Three models, the M-Class, E350 sedan and the GLK250, carry the mill, which has aftertreatment systems and emissions reducers not seen in Europe.

With a base price of $38,950, the GLK250, already on dealer lots, compares favorably to the GLK350, priced at $37,090. With a 4-cyl. engine, the model manages to avoid the upcharge commonly associated with diesels.

The GLK250 also adds Mercedes’ BlueTEC and 4Matic technologies. BlueTEC reduces emissions while 4Matic enables permanent all-wheel drive. Both functions are baked into the base price.

The 2.1L 4-cyl. inline engine, mated to a 7-speed automatic transmission, makes 200 hp and 369 lb.-ft. (500 Nm) of torque. Our test here is to determine whether these technologies working together deliver the performance Mercedes-Benz is known for.

It’s a rainy day in the downtown suburb, where our trip begins. The streets of the cosmopolitan college town feature a smorgasbord of vehicle offerings, and it’s not unlikely to spot a diesel-powered Benz.

We testers have a choice between lower-end GLK models and top-end editions loaded with optional equipment. We land in one of the higher-end CUVs that includes parking assist, a Harman/Kardon sound system, heated seats, rearview camera, blindspot assist, lane-keeping assist, navigation and a color touchscreen in the center stack.

While all these perks are nice, and they do make a Mercedes a Mercedes, they simply ratchet the price up to $57,635, which may turn off thrifty customers looking to save with the projected reduced costs of diesel fuel. But not all Mercedes buyers are thrifty.

The test route leads out of Ann Arbor and into rural Washtenaw, Livingston and Jackson counties, a mix of tight, hilly roads dotted with fading red barns, general stores and tiny churches with big steeples. Because of the dreary conditions, the optional premium lighting package that includes bi-xenon headlamps and adaptive highbeam assist, comes in handy.

At idle, the chug of the diesel mill is noticeable. Fortunately, the vibration is absorbed so it doesn’t feel like we’re sitting on top of the engine.

That chug disappears in motion, where the vehicle becomes a pleasant ride at speeds between 40 and 60 mph (64.3 and 96.6 km/h). But for this GLK250, accelerating between 40 and 50 mph (64.3 and 80.4 km/h) is a bit taxing and there’s a noticeable choke getting it past 60 mph, especially uphill.

Keeping the speed around 60 mph also takes some extra footwork avoided by going into cruise control. It’s a little disappointing, especially compared with less-expensive SUVs and CUVs.

Cruising at that speed not only calls for some extra lead on the pedal, but the engine sounds overworked in doing so. It’s not an unpleasant noise, but it’s enough to raise an eyebrow.

The GLK250 manages to be light enough for the engine to push it along, but still absorbs bumps. All-wheel drive maintains balance while negotiating wet roads, and braking is adequate.

For the most part, the interior is quiet but feels average compared with other top-end Mercedes models. It matches the $38,000 base, but doesn’t quite provide the environment expected of a vehicle nearing the $60,000 mark.

Where the GLK250 stands out is fuel economy. Mercedes lists a combined fuel economy at 28 mpg (11.9 L/100 km), with 24 mpg city (10.2 L/100km) and 33 mpg highway (14.0 L/100 km). Even with varying speeds along the 60-odd-mile course, the vehicle notched 34.6 mpg (14.7 L/100 km) and the needle on the fuel gauge barely starts to dip.

One mild annoyance about the GLK250, and many other vehicles that carry this technology: the ultra-sensitive lane-keeping assist, which is set off along narrower roadways. Thankfully this function can be turned off.

Mercedes’ key selling point here is the GLK250’s clean-diesel engine, which it says puts the CUV in a class by itself compared with offerings from BMW, Audi and Lexus. Its closest counterpart, the auto maker says, might be the hybridized Audi Q5.

While the GLK250 looks and performs like other entries in the nascent small-luxury CUV field, the diesel mill certainly makes it worth a second look. Status seekers who aren’t big on performance but hate making trips to the gas pump should keep the GLK250 at the top of their shopping lists.

afoley@wardsauto.com

'13 Mercedes-Benz GLK250 BlueTEC 4MATIC
Vehicle type Four-door, five-passenger cross/utility vehicle
Engine Inline four-cylinder turbodiesel
Power (SAE net) 200 hp
Torque 369 lb.-ft. (500.3 Nm)
Bore x stroke (mm) 82.8 x 98.8
Compression ratio 16:2:1
Transmission Seven-speed automatic
Wheelbase 108.5 in. (275.6 cm)
Overall length 178.3 in. (452.9 cm)
Overall width 74.25 in. (188.6 cm)
Overall height 66.9 in. (169.9 cm)
Curb weight TBD
Base price $38,590
Fuel economy 24 highway/33 city/28 combined (11.9/10.2/14.0 L/100 km)
Competition Audi Q5 Hybrid, Acura RDX, BMW X3, Land Rover Evoque, Cadillac SRX, Infiniti EX, Volvo XC60
Pros Cons
Great fuel numbers A little sluggish overall
Nice interior Add-ons get pricey
Quiet, smooth ride Chuggy at idle